Problem: $ { \left[\begin{array}{rr}{1} & {4} \\ {4} & {4} \\ {1} & {2}\end{array}\right]-\left[\begin{array}{rr}{2} & {-2} \\ {0} & {2} \\ {1} & {-2}\end{array}\right] = {?} } $
Answer: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rr}{1}-{2} & {4}-{-2} \\ {4}-{0} & {4}-{2} \\ {1}-{1} & {2}-{-2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{-1} & {6} \\ {4} & {2} \\ {0} & {4}\end{array}\right]}$